Introducer sheath for catheters

ABSTRACT

An introducer sheath includes a tubular body portion having a proximal region and a distal region, and defines an internal lumen configured and dimensioned to slidably receive a catheter. A penetrating portion at a distal end of the tubular body has a first tapered configuration to enlarge an opening in a body tissue during distal advancement of the introducer sheath through the body tissue and a second expanded configuration to enable the passage of a distal end portion of a catheter through the penetrating portion.

TECHNICAL FIELD

The present disclosure relates to catheter assemblies and, moreparticularly, to an introducer sheath for placement of a catheter into abody.

BACKGROUND

Catheters are flexible medical instruments for use in the withdrawal andintroduction of fluids to and from body cavities, ducts, and vessels.Catheters have particular application in hemodialysis procedures, inwhich blood is withdrawn from a blood vessel for treatment andsubsequently returned to the blood vessel for circulation through apatient's body. Catheters may also be used for other procedures andinclude central venous catheters, dialysis catheters, peripheralcatheters and neurology catheters.

Various techniques are employed for the insertion of catheters into thebody including, but not limited to, the use of guidewires, introductionstylets or obturators, dilator/sheath assemblies, and the like. Forexample, during such procedures, a hollow needle cannula may be insertedinto a target vessel in, for example, the venous system, to create avenotomy (entry) site. Upon positioning the needle cannula within thetarget vessel, a guidewire is inserted through a proximal end of theneedle cannula, into the target vessel, and advanced to a desiredlocation within the target vessel. The needle cannula is then withdrawn,leaving a distal end of the guidewire positioned within the targetvessel at the desired location, and a proximal end of the guidewireextending outwardly from the venotomy site. A dilator/sheath assembly isthen threaded over the guidewire and into the vessel through thevenotomy site to expand the venotomy site and target vessel to helpinsert the flexible catheter. The separate dilator within the sheathprovides the structure at the distal end of the sheath to push throughand expand the tissue. The guidewire and dilator are then retracted fromthe site, leaving the sheath in position. The sheath typically includesa hemostatic valve to reduce the loss of blood and the aspiration of airtherethrough as the dilator is removed and before a catheter or otherinstrument is inserted into the sheath. A catheter may then beintroduced through the hemostatic valve and sheath, and advanced intoposition within the target vessel at which time the sheath may bewithdrawn from the vessel over the catheter such that the distal tip ofthe catheter remains in place within the vessel.

Although known insertion techniques have proven to be effective, itwould be advantageous to provide a device to enable for the insertion ofthe catheter into the circulatory system without the need for a separatedilator/obturator or hemostatic valve, thereby reducing the number ofinsertion accessories, procedure time, and cost. Such a device wouldenable the successful insertion of catheters having various tip designs(e.g., blunted, non-tapered, or split tips) to be inserted directly intothe vasculature with the sheath. The device would also enable thesuccessful insertion of catheters fabricated from various materials asthe device may be provided with varying degrees of stiffness. A stifferdevice, for example, may replace the need to use a stylet duringinsertion of softer catheters thereby further reducing the cost of acatheter kit, the number of components a clinician has to interact withduring a catheterization procedure, and the procedure time.

SUMMARY

The present introducer sheaths include a tubular body portion having aproximal region and a distal region and define an internal lumenconfigured and dimensioned to slidably receive a catheter. A penetratingportion at a distal end of the tubular body has a first taperedconfiguration to enlarge an opening in a body tissue during distaladvancement of the introducer sheath through the body tissue and asecond expanded configuration to enable the passage of a distal endportion of a catheter through the penetrating portion.

Methods of positioning a catheter within a body tissue are alsodescribed. In accordance with an embodiment of the present methods, acatheter assembly is provided. The catheter assembly includes a catheterdisposed within a tubular body of an introducer sheath, the tubular bodyincluding a proximal region and a distal region including a penetratingportion having a first configuration which is tapered towards a distalopening. An opening in the body tissue is then dilated with thepenetrating portion of the introducer sheath and the penetrating portionis expanded to a second configuration having a substantially uniformdiameter to accommodate passage of the catheter therethrough.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure will be described hereinwith references to the accompanying drawings, wherein:

FIG. 1 is a side, perspective view of an introducer sheath in accordancewith one embodiment of the present disclosure;

FIG. 2 is a side view of an exemplary catheter which may be utilizedwith the introducer sheath of the present disclosure;

FIGS. 3A and 3B are side, perspective views of the introducer sheath ofFIG. 1 and the exemplary catheter of FIG. 2 in a first configuration anda second configuration, respectively;

FIG. 3C is a side, perspective view of the introducer sheath of FIG. 1being maintained on the proximal end portion of the exemplary catheterof FIG. 2 in accordance with an embodiment of the present disclosure;

FIG. 4A is a side, perspective view of an introducer sheath inaccordance with another embodiment of the present disclosure;

FIGS. 4B and 4C are close-up views of the distal region of theintroducer sheath of FIG. 4A in a first configuration and a secondconfiguration, respectively;

FIG. 5A is a side, perspective view of an introducer sheath inaccordance with yet another embodiment of the present disclosure;

FIG. 5B is a close-up view of the distal region of the introducer sheathof FIG. 5A; and

FIGS. 6A and 6B are side, perspective views of an introducer sheath inaccordance with another embodiment of the present disclosure in a firstconfiguration and in a second configuration, respectively.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Various exemplary embodiments of the present disclosure are discussedherein below in terms of medical catheters for the administration offluids, such as withdrawal from and introduction to the body of apatient and, more particularly, in terms of catheters for vascularaccess. Vascular access catheters include, for example, central venouscatheters, acute dialysis catheters, chronic dialysis catheters, andperipheral catheters. However, it is envisioned that the principles ofthe present disclosure are equally applicable to a range of catheterapplications including surgical, diagnostic, and related treatments ofdiseases and body ailments of a patient. It is further envisioned thatthe principles relating to the presently disclosed catheter assembliesmay be equally applicable to a variety of catheter related procedures,such as, for example, hemodialysis, cardiac, abdominal, urinary, andintestinal procedures, in chronic and acute applications. Moreover, thepresently disclosed catheter assemblies can be used for administrationand removal of fluids such as, for example, medication, saline, bodilyfluids, blood and urine.

In the following discussion, the terms “proximal” and “trailing” may beemployed interchangeably, and should be understood as referring to theportion of a structure that is closer to a clinician during proper use.The terms “distal” and “leading” may also be employed interchangeably,and should be understood as referring to the portion of a structure thatis further from the clinician during proper use. As used herein, theterm “patient” should be understood as referring to a human subject orother animal, and the term “clinician” should be understood as referringto a doctor, nurse or other care provider and may include supportpersonnel.

The following discussion includes a description of the presentlydisclosed catheter assemblies and a description of an exemplarycorresponding method of use in accordance with the principles of thepresent disclosure. For the purposes of discussion, the catheter,introducer sheath, and other components will be discussed in terms of ahemodialysis catheter, and the corresponding method of use will bediscussed in terms of a procedure utilized for positioning a catheterinto the circulatory system. However, those skilled in the art willappreciate the presently disclosed catheter assemblies, and thecomponents thereof, have many other applications in addition to dialysisapplications, such as those described above.

Referring now to the figures, wherein like components are designated bylike reference numerals throughout the several views, FIG. 1 illustratesone embodiment of an introducer sheath 100 for use in the placement of acatheter in a patient, such as the catheter 150 seen in FIG. 2. Theintroducer sheath 100 includes a tubular body portion 102 having aproximal region 104 and a distal region 106. The body portion 102 of theintroducer sheath 100 defines an internal lumen 108 (shown in phantom inFIG. 1) that is configured and dimensioned to slidably receive thecatheter 150 (FIG. 2).

The distal region 106 of the introducer sheath 100 includes a distallytapered penetrating portion 110 that is configured and dimensioned toenlarge an opening formed in target tissue, such as a venotomy site,during distal advancement of the introducer sheath 100. The penetratingportion 110 is fixedly secured to, or monolithically formed with, thebody portion 102, and includes a distal opening 112 that is configuredand dimensioned to receive a guidewire (not shown). In one embodiment ofthe introducer sheath 100, it is contemplated that the distal opening112 may define an internal transverse dimension that substantiallyapproximates an outer dimension of the guidewire to minimize the surfacearea at the distal-most end of the penetrating portion 110, and therebyminimize trauma to the patient's tissue during introduction of theintroducer sheath 100 into a patient.

In the embodiment of the introducer sheath 100 illustrated in FIG. 1,the introducer sheath 100 includes one or more perforations 114, 115.The perforations 114 along the proximal region 104 may be, for example,diametrically opposed perforations to facilitate tearing or splitting ofthe introducer sheath 100. The perforations 115 along the distal region106 may be the same or distinct from perforations 114 and also mayinclude any number of additional rows of perforations to form thetapered configuration and facilitate expansion of the penetratingportion 110 of the introducer sheath 100. It should be understood thatthe placement and spacing of the perforations 114, 115 through theintroducer sheath 100 may vary along the length of the tubular body 102.Specifically, following placement of the catheter 150 (FIG. 2) into thetarget tissue as desired, the clinician can tear, or split, theintroducer sheath 100 along the perforation(s) 114 to facilitateseparation of the introducer sheath 100 from the catheter 150 (FIG. 2).To facilitate such tearing, the introducer sheath 100 may include manualgrips or members 116 positioned in the proximal region 104 of theintroducer sheath 100 that are configured and dimensioned formanipulation by the clinician.

Referring now to FIG. 2, an exemplary catheter 150 which may be utilizedwith the presently disclosed introducer sheaths will be discussed. Thecatheter 150 will be discussed, and illustrated in the correspondingfigures, as a dual lumen catheter. It should be appreciated, however,that the principles of the present disclosure are equally applicable tocatheters having alternative tip configurations, such as staggered tipor split-tip, catheters including a single lumen or multiple lumens,such as triple lumen catheters, and other catheters of variouscross-sectional geometries, and/or catheters that are employable in avariety of other medical procedures. For example, suitable non-exclusiveexamples of catheters falling within the scope of the present disclosureare the PALINDROME™ and MAHURKAR® Maxid™ catheters, each of which ismade available by Covidien, which maintains a principal place ofbusiness at 15 Hampshire Street, Mansfield, Mass.

Catheter 150 includes elongate body 152, catheter hub 160, and extensiontubes 162, 164. The elongate body 152 includes proximal end portion 154and a distal end portion 156, and defines lumens 158, 159 through whichfluid may be removed and/or returned to a patient's body. Lumens 158,159 of elongate body 152 are adapted to be fluidly coupled to catheterhub 160. Extension tubes 162, 164 extend proximally from catheter hub160 and may include adapters 166, 168, respectively, attached theretofor attachment to external devices. Clamps 170, 172 may also bepositioned on extension tubes 162, 164, respectively, to control theflow of fluid through extension tubes 162, 164 by inhibiting orpermitting the passage of fluid upon clamping or unclamping.

The introducer sheath 100 may be separately manufactured, such as byextrusion or molding, and inserted onto at least the distal end portion156 of catheter 150 prior to packaging. Alternatively, introducer sheath100 may be applied to the catheter 150 at any time prior to introductioninto the target vessel, wherein introducer sheath 100 may be chosen suchthat the internal lumen 108 of the introducer sheath 100 may define aninternal transverse dimension that substantially approximates an outerdimension of the elongate body 152 of catheter 150 thereby eliminatingthe need for the introducer sheath 100 to be valved at the proximalregion 104. Alternatively, however, the introducer sheath 100 mayinclude one or more hemostatic valves positioned within the internallumen 108 that are configured and dimensioned to inhibit fluidcommunication through the introducer sheath 100. In embodiments, thehemostatic valve may be a self-sealing membrane through which a cathetermay be introduced and removed without leakage of body fluids orintroduction of air therethrough.

FIGS. 3A and 3B illustrate catheter 150 positioned within introducersheath 100. In use, after placement of the guidewire within a targetvessel as described above, the clinician will insert the guidewire (notshown) through the distal opening 112 of the introducer sheath 100 suchthat the guidewire may be passed through the distal end portion 156 ofcatheter 150, through lumen 158 (FIG. 2), and out of the proximal endportion 154 of the catheter 150, such as out of one of the extensiontubes 162, 164. The penetrating portion 110 is provided in an initialtapered configuration so that the penetrating portion 110 may beintroduced into an opening of the target vessel, such as the venotomysite, and expands the opening during distal advancement of theintroducer sheath 100. After dilating the opening of the vessel andadvancing the introducer sheath 100 to the desired position, the distalend portion 156 of the catheter 150 may then be distally passed throughthe distal region 106 of the introducer sheath 100 by applying a forceto the catheter 150 in the distal direction to thereby break theperforations 115 in the sheath material of the penetrating portion 100(as shown in FIG. 3B) and continuing to advance the catheter 150 untilthe catheter 150 is properly positioned within the vessel.

Alternatively, the penetrating portion 110 may be fabricated from anysuitable material or combinations of materials which are sufficientlyextendible, expandable, pliable, malleable, ductile, compressible,elastic, and/or rubbery to provide for controlled expansion of thedistal opening 112 of the introducer sheath 100 upon passage of thecatheter 150 therethrough, while maintaining sufficient stiffness forinitial passage and dilation of the vessel. Examples of suitablematerials include, for example, one or more moldable and/orthermoformable plastics, polymers, urethanes, natural or syntheticrubbers, silicones, elastomer and/or elastomeric or latex materials.

The proximal region 104 of the introducer sheath 100 may then be crackedalong perforations 114 thereby breaking the perforations 114 in thesheath material until the introducer sheath 100 is separated into twoseparate pieces. The pieces may be removed by sliding the introducersheath 100 proximally towards the catheter hub 160 of the catheter 150until the material is completely removed from the insertion site. Inother embodiments, the introducer sheath 100 may remain on the catheter150, or only a portion of the introducer sheath 100 may be separated andremoved via perforations 114, as shown in FIG. 3C, such that theintroducer sheath 100 acts as a barrier between the patient's tissue andthe catheter 150. Moreover, by maintaining the introducer sheath 100 ora portion thereof on the catheter 150, the introducer sheath 100 mayfunction as a strain relief to increase the kink resistance of thecatheter 150 adjacent proximal end portion 154 of catheter 150. Furtherstill, the introducer sheath 100, or a portion thereof, may be treatedwith an antimicrobial material, or other medicaments, to help preventinfection at the venotomy site.

With reference now to FIGS. 4A and 4B, an introducer sheath 200 inaccordance with another embodiment of the present disclosure isprovided. The introducer sheath 200 is similar to the introducer sheath100 discussed above with respect to FIG. 1, and accordingly, will onlybe discussed with respect to any differences therefrom.

Introducer sheath 200 includes a tubular body portion 202 having aproximal region 204 and a distal region 206. The body portion 202 of theintroducer sheath 200 defines an internal lumen (FIG. 1) that isconfigured and dimensioned to receive a catheter, such as catheter 150illustrated in FIG. 2. The lumen defines a central longitudinal axis“X”. As discussed above in connection with the introducer sheath 100(FIG. 1), introducer sheath 200 may include one or more perforations214, such as diametrically opposed perforations, and manual grips ormembers 216 to facilitate tearing of the introducer sheath 200 along theperforation(s) 214.

The distal region 206 of introducer sheath 200 includes a penetratingportion 210 that may be cut at various locations around the distalopening 212 such that the cuts 218 form fingers 220 which are configuredto nest in a tapered configuration towards the distal opening 212 bybending the fingers 220 inwardly towards the central longitudinal axis“X”. In embodiments, the fingers 220 may extend over, overlie, overlap,or rest on one another. In other embodiments, the fingers 220 may lienext to and butt up against each other along cuts 218. The penetratingportion 210 of the distal region 206 has a first, or initialconfiguration in which a catheter does not extend therethrough and thefingers 220 are tapered to facilitate insertion of the penetratingportion 210 into a target vessel.

Alternatively, as illustrated in FIGS. 5A and 5B, distal region 306 ofintroducer sheath 300 may include at least one fold 322, or a pluralityof folds 322, formed or extending radially thereabout such that distalregion 306 tapers in a distal direction to a radially smaller diameterat or adjacent distal opening 312 to form penetrating portion 310. Asused herein, the term “fold” is understood to include a pleat,undulation, corrugation, crease, bend and the like. Generally, thefold(s) 322 will be at or near distal opening 312 such that the materialthat is folded, bent or undulating, can open-up, unfold, extend orexpand to enable a catheter to pass through the distal opening 312.

As shown in FIG. 4C, penetrating portion 210 may have one or moresecond, or subsequent configurations to accommodate the passage orextension of a catheter therethrough, in which the penetrating portion210 is at least partially or fully extended or expanded to have adiameter which is substantially equal to the diameter of the lumenextending through body portion 202. As can be seen, as the catheter 150is advanced through penetration portion 210, the fingers 220 split alongcuts 218 and splay outwardly to expand distal opening 212 therebyenabling passage of catheter 150. It is envisioned that the penetratingportion 210, 310 can be temporarily secured into the taperedconfiguration using an adhesive that is capable of dissolving orsoftening and separating once inserted into the vasculature, such as apolymer based adhesive. For example, a polysaccharide-based adhesivecould be employed that would weaken upon exposure to the body fluids ofthe patient's vasculature. Alternatively, the penetrating portion 210,310 may be temporarily secured into the tapered configuration by heatsetting the fingers 220 or folds 322. Further still, the fingers 220 orfolds 322 may be thermally bonded together to form the taperedconfiguration such that the thermal bond may be broken and thepenetrating portion 210, 310 expanded upon distal advancement of thecatheter 150.

FIGS. 6A and 6B illustrate an introducer sheath 400 which is fabricated,at least in part, from materials which are capable of adopting a shapein-vivo to aid in the insertion, placement, use, and withdrawal of acatheter in accordance with the present disclosure. In embodiments,shape memory polymeric materials may be utilized to form the introducersheath 400 of the present disclosure which possesses a permanent shapeat body temperature and a temporary shape at room temperature.

Shape memory polymers are a class of polymers that, when formed into anobject such as an introducer sheath, can be temporarily deformed bymechanical force and then caused to revert back to an original shapewhen stimulated by energy, such as heat, light, or electrical current.Shape memory polymers exhibit shape memory properties by virtue of atleast two phase separated microdomains in their microstructure. Thefirst domain is composed of hard, covalently cross-linked or otherwisechain motion-limiting structures, which act as anchors to retain theobject's original shape. The second domain is a switchable softstructure, which can be deformed and then fixed to obtain a secondary ortemporary shape.

In the case of heat stimulated shape memory polymers, a transitiontemperature (T_(Trans)) exists at which the shape change occurs duringheating. The shape memory polymers can thus be tailored by alteringmaterial properties at the molecular level and by varying processingparameters. An object's primary shape may be formed with heat andpressure at a temperature at which the soft domains are flexible and thehard domains are not fully formed. The object may then he cooled so thatthe hard domains are more fully formed and the soft domains becomerigid. The secondary or temporary shape can be formed by mechanicallydeforming the object, which is most readily accomplished at atemperature approaching or above T_(Trans). Mechanical stressesintroduced into the object are then locked into place by cooling theobject to temperatures below T_(Trans), so that the soft segmentssolidify to a rigid state. Once the object is heated to T>T_(Trans), thesoft segments soften and relax back to their original configuration andthe object returns to its primary shape, sometimes referred to herein,as its permanent shape. The temperature at which a shape memory materialreverts to its permanent shape may be referred to, in embodiments, asits permanent temperature (T_(perm)).

Polymers possessing shape memory properties which may be used toconstruct introducer sheaths in accordance with the present disclosureinclude biocompatible and non-biodegradable materials. In embodiments,the shape memory polymer may be a copolymer of different biocompatiblematerials, such as materials having different thermal characteristics.In embodiments, the shape memory polymer may be a blend or mixture oftwo or more materials to create a polymeric material having the desiredphysical properties. Other shape memory materials, including shapememory metals and metal alloys such as Nitinol, may also be used to formthe introducer sheaths of the present disclosure.

In embodiments, the shape memory material is a crosslinked polyurethanemade by using excess diisocyanate or by using a crosslinker such asglycerin or trimethylol propane. However, other suitable non-degradablematerials may be employed, so long as the T_(trans) temperature isbetween room and body temperatures. Specifically, it is desired that atleast a penetrating portion 410 be harder at room temperature andsofter, or pliable, at body temperature and relax to a permanent shapethrough which the catheter 150 may pass.

As illustrated in FIGS. 6A and 6B, introducer sheath 400 includes atubular body portion 402 having a proximal region 404 and a distalregion 406. The body portion 402 of the introducer sheath 400 defines aninternal lumen (FIG. 1) that is configured and dimensioned to receive acatheter, such as catheter 150. As discussed above in connection withthe introducer sheath 100 (FIG. 1), introducer sheath 400 may includeone or more perforations 414, and manual grips or members (not shown) tofacilitate tearing of the introducer sheath 400 along the perforation(s)414. Alternatively, introducer sheath 400 may include suture wing 416 tosecure introducer sheath 400 to the patient in embodiments in whichintroducer sheath 400 is left on the catheter 150 as a strain reliefand/or antimicrobial barrier.

At least the distal region 406 of the introducer sheath 400 isfabricated from a shape memory polymeric material which is compressedinto a temporary shape such that the penetrating portion 410 tapers tothe distal opening 412. Transformation from the temporary shape to thepermanent shape, as illustrated in FIG. 6B, such as by placement withina patient's body to heat the shape memory polymeric material, results inthe radial expansion of the penetrating portion 410 to enable thecatheter 150 to pass therethrough.

The proximal region 404 of the introducer sheath 400 may then be crackedalong the perforations 414 to remove the introducer sheath 400 fromcatheter 150. Alternatively, the introducer sheath 400 may slideproximally in the direction of arrows “p” towards the catheter hub 160to retain the introducer sheath 400 on the catheter 150 as discussedabove and sutured in place using suture wings 416. In embodiments,catheter hub 160 may include fastening means, such as hooks, detents, orsnaps, to facilitate the retention of the introducer sheath 400 incontact with the hub 160 of catheter 150. It is envisioned that bodyportion 402 of the introducer sheath 400 may vary in length depending onthe type of catheter that is to be inserted therethrough and theparticular surgical application in which the particular device is goingto be used, such as removing the introducer sheath 400 or retaining atleast a portion of the introducer sheath 400 on the catheter 150.

In embodiments, a molding process may be utilized to produce anintroducer sheath 400 of the present disclosure. Plastic molding methodsare within the purview of those skilled in the art and include, but arenot limited to, melt molding, solution molding, and the like. Injectionmolding, extrusion molding, compression molding and other methods canalso be used as the melt molding technique. Once placed in the mold withthe proper dimensions and configuration, the polymeric material used toform the introducer sheath may be heated to a suitable temperature(e.g., the permanent temperature (T_(perm))), which may, in embodiments,be the melting temperature of the shape memory polymeric materialutilized to form the introducer sheath. Heating of the introducer sheathmay be at suitable temperatures for a period of time sufficient toobtain the permanent shape and dimensions.

The temperature for deformation treatment of the introducer sheathmolded with a previously memorized shape is one that makes possibleready deformation without producing cracks and should not exceed thetemperature adopted for the shape memorization (e.g., T_(perm)).Deformation treatment at a temperature exceeding that for the originalshape memorization may cause the object to memorize a new permanentshape.

After an introducer sheath with the desired shape has been formed, theintroducer sheath may be deformed at a deforming temperature to obtainan alternate, temporary shape.

Suitable temperatures for deformation will vary depending on the shapememory polymer utilized, but generally may be above the transitiontemperature of the polymer (T_(trans)), but below the T_(perm). Inembodiments, the shape memory polymer may be cooled from its T_(perm) toa lower temperature which remains above the T_(trans) and deformed, inembodiments by hand and/or mechanical means. There are no particularlimitations on the manner in which deformation can be achieved. In otherembodiments, the introducer sheath may be deformed to room temperature(about 20° C. to about 25° C.) to obtain its temporary shape, althoughthe temperature may differ depending upon the particular polymeremployed. The introducer sheath may then be cooled to a temperaturebelow the T_(trans) of the material utilized to form the introducersheath, at which time the introducer sheath of the present disclosure isready for use. As the T_(trans) is usually greater than roomtemperature, in embodiments cooling to room temperature may besufficient to form the temporary shape.

The introducer sheaths thus prepared recover their originally memorizedshape upon application of energy, such as heating, either by placementin a patient's body and heating with body heat (about 37° C.), or theaddition of exogenous heat at a prescribed temperature, in embodimentsabove the T_(trans) of the shape memory polymer utilized. The higher thetemperature for heating, the shorter the time for recovery of theoriginally memorized shape. In embodiments in which a higher shapememory temperature is desired, heating can be accomplished by using agas or liquid heating medium, heating devices, ultrasonic waves,electrical induction, chemical reaction, and the like. The means forthis heating, however, is not limited. Of course, in an applicationinvolving a living body, care must be taken to utilize a heatingtemperature which will not cause burns. Examples of liquid heating mediainclude physiological saline solution, alcohol, combinations thereof,and the like.

As described above, medicinal agents may be incorporated into orprovided on the various disclosed introducer sheaths. Medicinal agentsthat may be incorporated into or provided on the disclosed introducersheath and/or on an internal surface of the lumen of the introducersheath may include antimicrobial agents, anti-virals, anti-fungals,anti-thrombogenics, anti-stenotics and the like, and combinationsthereof. Antimicrobial agents as used herein is defined by an agentwhich by itself or through assisting the body (immune system) helps thebody destroy or resist microorganisms which may be pathogenic (diseasecausing). The term “antimicrobial agent” includes antibiotics, quorumsensing blockers, surfactants, metal ions, antimicrobial proteins andpeptides, antimicrobial polysaccharides, antiseptics, disinfectants,anti-virals, anti-fungals, and combinations thereof.

Methods for combining medicinal agents with an introducer sheath of thepresent disclosure are within the purview of those skilled in the artand include, but are not limited to, coating, compounding, spraying,wicking, solvent evaporating, dipping, brushing, vapor deposition,coextrusion, capillary wicking, film casting, molding and the like. Itis envisioned that the medicinal agent may be applied to the presentintroducer sheath in any suitable form of matter, for example, films,powders, liquids, gels and the like.

Persons skilled in the art will understand that the devices and methodsspecifically described herein and illustrated in the accompanyingdrawings are non-limiting exemplary embodiments. It is envisioned thatthe elements and features illustrated or described in connection withone exemplary embodiment may be combined with the elements and featuresof another without departing from the scope of the present disclosure.As well, one skilled in the art will appreciate further features andadvantages of the invention based on the above-described embodiments.Accordingly, the invention is not to be limited by what has beenparticularly shown and described, except as indicated by the appendedclaims.

1. An introducer sheath comprising: a tubular body portion having aproximal region and a distal region and defining an internal lumenconfigured and dimensioned to slidably receive a catheter; and apenetrating portion at a distal end of the tubular body portion having afirst tapered configuration to enlarge an opening in a body tissueduring distal advancement of the introducer sheath through the bodytissue and a second expanded configuration to enable the passage of adistal end portion of a catheter through the penetrating portion, thepenetrating portion being separable from the tubular body portion viaperforations and configured to be maintained on the catheter to act as abarrier between body tissue and the catheter and to increase a kinkresistance of the catheter adjacent a proximal end portion of thecatheter.
 2. The introducer sheath of claim 1, wherein the introducersheath further comprises perforations along at least a portion of thetubular body to facilitate removal of the sheath from the catheter. 3.The introducer sheath of claim 2, wherein the perforations formed in theproximal region are different from the perforations formed in the distalregion of the tubular body.
 4. The introducer sheath of claim 1, whereinthe penetrating portion further comprises perforations, wherein theperforations break upon transition from the first configuration to thesecond configuration as the catheter is advanced towards the distalregion.
 5. The introducer sheath of claim 1, further comprising amedicinal agent coated on at least a portion of the introducer sheath.6. The introducer sheath of claim 1, further comprising manual gripsproximate to the proximal region.
 7. The introducer sheath of claim 1,wherein the penetrating portion terminates in a blunt distal opening.